This application relates to a supply duct for supplying cooling air with minimal pressure loss.
Gas turbine engines are known and, typically, include a fan delivering air into a compressor. The air is compressed and delivered into a combustor section where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors driving them to rotate.
The products of combustion are quite hot and cooling air is typically provided to a number of locations within the gas turbine engine.
In addition, the flow of air to the combustor section is closely controlled. Often, a diffuser is positioned immediately upstream of the combustor section and serves to prepare the air for delivery into the combustor section. Due to various packaging realities, the airflow downstream of the diffuser is turned through an approximately 90 degree angle and then back into an inlet through another 90 degree angle.
In the prior art, this same airflow is utilized as a source of cooling air.